Embodiments of the invention generally relate to a control system of a gas turbine engine, and more particularly, to a system for electrical augmentation of a gas turbine engine.
A gas turbine engine typically includes at least one spool having a turbine and a gas generator compressor mounted thereto, a source of heat positioned between the turbine and the compressor, a shaft and a free turbine mounted to the shaft, and a control system for transferring power between the spool and the shaft. For transient loads, gas generator acceleration may be needed to create an increased mass flow for a higher output. A relatively high percentage of total required gas turbine engine surge margin is typically needed to accommodate engine transients, particularly accelerations. This requirement can limit compressor efficiency and therefore overall engine efficiency, because, in general, increased surge margin requires lower compressor loading which results in lower compressor efficiency.
Therefore, a need exists for gas generator augmentation to support increased gas turbine engine compressor efficiency.